TABLE 1

MIC distribution and antimicrobial activity of ceftriaxone when tested against specific serogroups/types of S. pneumoniaea

Serogroup/type (no. tested)MIC (μg/ml)No. (cumulative %) of isolates inhibited at MIC (μg/ml) of:
50%90%≤0.060.120.250.51248>8
All (1,190)≤0.061688 (58.0)118 (67.9)67 (73.5)65 (79.0)146 (91.3)88 (98.7)6 (92.4)8 (99.9)1 (100.0)
3 (96)≤0.060.2584 (87.5)2 (89.6)9 (99.0)0 (99.0)1 (100.0)
4 (5)≤0.065 (100.0)
6A/6B (20)0.2525 (25.0)2 (35.0)3 (50.0)6 (80.0)1 (85.0)3 (100.0)
6C/6D (69)0.25122 (31.9)3 (36.2)10 (50.7)27 (89.9)6 (98.6)0 (98.6)0 (98.6)1 (100.0)
7C/7B/40 (18)≤0.06≤0.0617 (94.4)1 (100.0)
7F/7A (29)≤0.06≤0.0629 (100.0)
8 (15)≤0.060.2512 (80.0)0 (80.0)2 (93.3)1 (100.0)
9N/9L (34)≤0.06≤0.0633 (97.1)1 (100.0)
9V/9A (5)10 (0.0)0 (0.0)0 (0.0)2 (40.0)1 (60.0)2 (100.0)
10A (22)≤0.060.2519 (86.4)0 (86.4)1 (90.9)0 (90.9)2 (100.0)
11A/11D (71)≤0.06≤0.0666 (93.0)3 (97.2)1 (98.6)0 (98.6)0 (98.6)1 (100.0)
12F/12A/44/46 (13)≤0.060.1211 (84.6)2 (100.0)
13 (9)≤0.068 (88.9)1 (100.0)
14 (2)≤0.061 (50.0)0 (50.0)0 (50.0)0 (50.0)1 (100.0)
15A/15F (50)0.120.513 (26.0)20 (66.0)10 (86.0)4 (94.0)3 (100.0)
15B/15C (66)≤0.060.2541 (62.1)14 (83.3)11 (100.0)
16F (22)≤0.060.1219 (86.4)1 (90.9)0 (90.9)0 (90.9)1 (95.5)1 (100.0)
17F (20)≤0.060.1216 (80.0)2 (90.0)1 (95.0)0 (95.0)0 (95.0)1 (100.0)
18 (18A/18B/18C/18F) (1)≤0.061 (100.0)
20 (11)≤0.06≤0.0611 (100.0)
21 (12)≤0.060.58 (66.7)0 (66.7)1 (75.0)3 (100.0)
22F/22A (68)≤0.06≤0.0664 (94.1)1 (95.6)0 (95.6)1 (97.1)1 (98.5)0 (98.5)1 (100.0)
23A (75)0.120.2519 (25.3)41 (80.0)9 (92.0)3 (96.0)2 (98.7)1 (100.0)
23B (53)≤0.060.1233 (62.3)16 (92.5)1 (94.3)1 (96.2)1 (98.1)1 (100.0)
23F (4)0.121 (25.0)1 (50.0)0 (50.0)0 (50.0)1 (75.0)1 (100.0)
24 (24A/24B/24F) (2)≤0.061 (50.0)0 (50.0)1 (100.0)
28F/28A (1)≤0.061 (100.0)
31 (30)≤0.06≤0.0630 (100.0)
33F/33A/37 (20)≤0.06≤0.0619 (95.0)0 (95.0)0 (95.0)0 (95.0)1 (100.0)
34 (16)≤0.060.514 (87.5)0 (87.5)0 (87.5)2 (100.0)
35F/47F (13)≤0.06≤0.0613 (100.0)
38/25F/25A (12)≤0.06≤0.0612 (100.0)
48 (1)≤0.061 (100.0)
Nontypeable (11)0.514 (36.4)0 (36.4)1 (45.5)2 (63.6)4 (100.0)
35B (92)117 (7.6)0 (7.6)0 (7.6)11 (19.6)70 (95.7)4 (100.0)
19A (164)1222 (13.4)6 (17.1)6 (20.7)2 (22.0)47 (50.6)70 (93.3)4 (95.7)6 (99.4)1 (100.0)
19F (35)≤0.06226 (74.3)1 (77.1)0 (77.1)0 (77.1)3 (85.7)3 (94.3)1 (97.1)1 (100.0)
  • a The CLSI and EUCAST breakpoints for ceftriaxone susceptibility are ≤1 μg/ml and ≤0.5 μg/ml, respectively.